Franklin Wastewater Treatment Plant - Executive Summary |
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EXECUTIVE SUMMARY RISK MANAGEMENT PLANT GENERAL AUTHORITY OF THE CITY OF FRANKLIN FRANKLIN WASTEWATER TREATMENT PLANT ONE ELK STREET FRANKLIN VENANGO COUNTY PENNSYLVANIA FACILITY The Franklin Wastewater Treatment Plant is located on the west bank of the Allegheny River at the southern end of Franklin. The original plant was constructed in 1939 and provided primary treatment of wastewater. During the mid-1970's, the plant was renovated and enlarged to provide secondary treatment of wastewater and storm water treatment. The plant is designed to provide secondary treatment up 5,000,000 gallons per day and in addition storm water treatment of 12,000,000 gallons per day. The plant serves all of the City of Franklin and portions of Sugarcreek Borough, Sandycreek Township and Frenchcreek Township. Chlorine gas is used to disinfect the effluent of the secondary treatment process and the storm water treatment process. The chlorine is received at the treatment plant in containers that contain 2,000 pounds of liquid chlorine. The maximum amount of liquid chlorine stored at the treatment plant is 12,000 pounds. Containers being used in the disinfection process are in an enclosed room. Empty containers and full containers are stored on a covered porch outside the chlorination building. PREVENTION POLICY AND PROGRAM The safe storage and handling of chlorine for the treatment process at the treatment plant is management's utmost concern both for plant personnel and the public. The plant is surrounded by a security fence to restrict unauthorized personnel from entering the plant during off-duty hours. Most chlorine gas leaks occur not directly from the chlorine cylinders but rather from the equipment used to dispense the gas in the treatment process. The cylinders that are in use in the treatment process and the chlorination equipment are housed in a building. The room that they are in is monitored continuously by a chlorine gas leak detector. In the event of a gas leak, the detector provides an audible and visual alarm. During off-duty hours, the chlorine gas leak detector is connected to an automatic telephone dialer that can deliver a prerecorded message to the plant personnel and the Franklin Police Department that there is a chlorine gas leak. Plant personnel attend training seminars on the safe handling and storage of chlorine that are sponsored by various industry organizations when the seminars are available, which is normally annually. Often, training seminars are held at the plant for plant personnel and the personnel from nearby municipalities. The key to limiting chlorine gas leaks is preventive maintenance. The chlorination equipment is inspected and maintained quarterly by a maintenance contractor. Key components of the chlorination system, which experience has shown will leak given sufficient time, are replaced well prior to the end of their normal life expectancy. EMERGENCY RESPONSE PROGRAM Two emergency response programs are in effect for the treatment plant. The first program is a plant policy designed to handle minor leaks. The second program is the City of Franklin Emergency Operations Plan, which is coordinated with the Venango County Emergency Management Agency, and would be instituted in the event of a major, catastrophic chlorine leak. Following are the essential points of the plant policy. The Franklin Fire Department responds to all chlorine leaks. No fewer than three individuals wearing self contained breathing apparatus (SCBA) must be available before any attempt is made to investigate a chlorine leak. One or more individuals wearing SCBA are stationed at the Fire Department equipment outside the plant area. Two individuals wearing SCBA go to the chlorine building to investigate the leak. Radio contact is maintained at all times between the individuals at the chlorine building and the fire equipment. One of the two individuals at the chlorine building will enter the bui lding and turn off the chlorine cylinder. The other individual is stationed at the door outside the building to assist the individual inside the building with evacuation in the event of an emergency. After the leak has been stopped, the individuals at the chlorine building will check the exterior of the building and adjoining areas to determine if anyone is in the area. If the area is clear, the chlorine in the chlorine building will be removed by exhaust fan, the cause of the leak will be determined and the problem corrected. Fire Department personnel will be released once the site is secure. The City of Franklin Emergency Operations Plan is a broad-based document which is designed to address every conceivable emergency situation. It describes the city and the city organization and facilities, the warning system and the vulnerability to various hazards. The plan provides for the administrative establishment of emergency operations, the function of elected officials and emerge ncy management personnel, the declaration of a disaster, unmet needs, interjurisdictional assistance, direction and coordination, continuity of government and phases of emergency management. The plan also indicates the organization and responsibilities of city council members, city departments and agencies, city emergency management agency staff and other supporting organizations and the municipality. Finally, the plan establishes administration and logistics, authority and references, and training and exercises. FIVE YEAR ACCIDENT HISTORY During the past five years, three minor chlorine leaks occurred. No injuries occurred offsite or onsite. No evacuations were necessary and the amount of chlorine released was minimal. WORST-CASE RELEASE SCENARIO The worst-case scenario is based on the entire contents of a chlorine cylinder, 2,000 pounds, being released out-of-doors during a ten minute period. The model used in developing the worst-case scenario is RMP Comp, Vers ion 1.06, as provided by the EPA. The toxic endpoint would be 1.3 miles from the plant based on a wind speed of 3.4 miles per hour and an air temperature of 77 degrees F. The most likely direction the release would travel is either upstream or downstream from the plant because the plant is bounded to the east and west by hills that are approximately 500 hundred feet in height. Along the east bank of the Allegheny River, opposite the plant, is US Route 322, a heavily-traveled highway, and a small residential community that could be impacted by a release when the wind was blowing from the east. To the southeast of the plant along the Allegheny River the impact would be minimal since the area is sparsely populated with primarily seasonal camps and cottages. The area that would be impacted the most is that portion of the City of Franklin to the north of the plant if the wind were blowing from the south. The toxic endpoint would be in the approximate area of Tenth Street with an estim ated population of 2,380 residing in the area to the south of Tenth Street. Based on a wind speed of 3.4 miles per hour, the chlorine gas would reach Tenth Street in 23 minutes. To mitigate the consequences of the worst-case scenario, the City of Franklin is considering several measures. Among the measures are: reducing the quantity of chlorine stored on site and the size of the container in which it is stored; eliminating chlorine as a disinfectant in the treatment process; storing chlorine in an enclosure; installing an alarm system in the area where chlorine is stored in the out of doors to detect any leakage. ALTERNATIVE RELEASE SCENARIO The alternative release scenario is based on a leak in the line that connects the chlorine cylinder to the chlorination equipment within the chlorine building. The amount of chlorine released would be 50 pounds and the duration would be ten minutes. The model used is RMP Comp, Version 1.06, as provided by the EPA. Based on a wind speed of 6.7 miles per hour and an air temperature of 77 degrees F, the toxic endpoint would be 0.1 miles from the chlorine building. The chlorine would travel off the plant site but would have little offsite impact since no residences or businesses are located within 0.1 miles of the plant. Additionally, prior to venting the chlorine building following a leak, the area of the Allegheny River adjacent to the plant is checked to insure there are no people in the area. This alternative release scenario was chosen because it most closely resembles leaks that do occur, albeit infrequently. PLANNED CHANGES TO IMPROVE SAFETY As mentioned above in the worst-case release scenario, several mitigation measures are being considered to improve overall safety. Likewise, as mentioned above in the prevention policy and program, plant personnel avail themselves of every opportunity to attend training on the safe use and handling of chlorine. Chlorine safety is the highest priority at the treatment pla nt. |